Reaction mass of ethane-1,2-diol and 2-hydroxyethyl formate and ethylene diformate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June - September 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

28 July 2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of ethane-1,2-diol and 2-hydroxyethyl formate and ethylene diformate

EC Number:

944-390-9

Molecular formula:

not applicable, multiconstituent substance

IUPAC Name:

Reaction mass of ethane-1,2-diol and 2-hydroxyethyl formate and ethylene diformate

Test material form:

liquid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

EpiSkinTM Small Model (EpiSkinTMSM), EPISKIN SNC Lyon, France, is a three-dimensional human epidermis model (see also below "any other information on materials and methods incl. tables").

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

A volume of 50 μL test material was applied evenly to the epidermal surface of the two test skin units respectively.

Duration of treatment / exposure:

The plates with the treated epidermis units were incubated for the exposure times of 4 hours at room temperature in the first experiment and 4 hours, 1 hour and 3 minutes at room temperature in the additional experiment. Negative controls were incubated for the exposure times of 4 hours at room temperature in the first experiment and 4 hours, 1 hour and 3 minutes at room temperature in the additional experiment. The positive control was tested only for the 4 h exposure time in both occasions (first and additional experiment).

Number of replicates:

2 replicates of the test material (for each exposure time) and 2 replicates negative control (for each exposure time) + 2 replicates positive control (for the 4 h exposure only). NaCl (9 g/L saline) and glacial acetic acid treated epidermis were used as negative and positive controls respectively.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

First experiment

Value:

15

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Second experiment (4 h exposure)

Value:

1

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Second experiment (1 h exposure)

Value:

82

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Results 4

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Second experiment (3 min exposure)

Value:

101

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Positive and negative controls showed the expected cell viability values within acceptable limits. All assay acceptance criteria were met, the experiment was considered to be valid.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (corrosive) based on GHS criteria

Conclusions:

The results indicate that the test material is corrosive to skin after 4 hours exposure and not corrosive after 1 hour and 3 minutes exposure. According to the UN GHS classification systems, the test material has been categorized as “Corrosive: Optional Sub- categories 1B and 1C”.

Executive summary:

EpiSkinTM SM test of the test material has been performed to predict its corrosion potential by measurement of its cytotoxic effect, as reflected in the MTT assay according to the OECD Test Guideline No. 431, 28 July 2015.

NaCl (9 g/L saline) and glacial acetic acid treated epidermis were used as negative and positive controls respectively.

Since according to the first experiment results the test material was corrosive after 4 hours exposition, an additional experiment was performed. In this experiment, the 4 hours exposure was repeated during and an additional 3 minutes and 1 hour exposure period included.

Disks of EPISKIN (two units) were used for each test material exposure period as well as for negative and positive control.

Exposure of test material was terminated by rinsing with PBS 1x solution. The viability of each disk was assessed by incubating the tissues for 3 hours with MTT solution at 37°C in 5% CO₂ protected from light. The formazan precipitate was then extracted using acidified isopropanol and quantified spectrophotometrically.

For each treated tissue viability was expressed as a % relative to negative control. The test material is considered to be non-corrosive to skin, if the mean relative viability after 4 hours of exposure is above or equal 35 % of the negative control.

The test material showed significantly reduced cell viability (below 35 %) in comparison to the negative control after 4 hours of exposure in both experiments. In the first experiment the average test material treated tissue viability was 15% and in the additional experiment 1% at 4 hours of exposure.

In the additional experiment the test material treated tissue viabilities were above 35 % of the mean negative control value after 1 hour and 3 min of exposure (82 % at 1 hour and 101 % at 3 minutes of exposure).

Positive and negative controls showed the expected cell viability values within acceptable limits.

All assay acceptance criteria were met, the experiment was considered to be valid.